Fluvial Geomorphologists
Who classifies streams based on two levels; geomorphic characteristics based on basin relief and bed material and slope
Rosgen
What is stream order?
Classification based on distribution of stream in a channel network
What is the difference between infiltration and percolation
infiltration: Water flowing into soil
percolation: Water moving through soil
What are the two numbers calculated to determine flow characteristics?
Reynolds and Froude
What is the difference between ephemeral, intermittent, and perennial streams
flows in response to storms, flows some of the year, flows year round
Who were the two early geomorphologists that had differing views on how landscapes formed?
Davis and Gilbert (and what were their views?)
What maintains equilibrium?
Negative feedback
What factors (4) control what fraction of precipitation becomes runoff?
geology, topography, vegetation, and climate
What is the difference between Steady and Unsteady
Steady: depth and velocity don't change with time
Unsteady: they do
What are flow regimes
Show seasonal variation in stream discharge that is averaged over a long period of time
What did Schumm use to classify alluvial rivers and streams?
based on sediment load, channel stability, and channel pattern
How are rivers systems?
They have inputs and outputs, changes in one aspect of the system produces multiple side effects, and they have feedback that affect system (examples?)
What are the different flows of interest that are typically studied and why?
Low flow: Used for water quality, water supply, and NPDES
Bankflow discharge: breakpoint between channel and floodplain formation, used to estimate channel forming discharge
high flow: move sediment, shape channel, causes flooding
Grain roughness (due to roughness of sediment) and Form roughness (caused by obstruction)
What are the 5 mechanisms of landscape change
uplift, subsidence, erosion, deposition, and volcanism
Who classified channels based on channel patter, frequency of islands, and bar type?
Kellerhal
What are internal and external variables of a fluvial system (4 examples each?)
Internal influenced by both internal and external variables: Topography, geology, soil, and vegetation
External originate from outside the system, independent: Climate, Tectonics, base level, and human activity
Describe the three main ideas about runoff productions
Hortonian: rainfall occurs as the thin sheet over entire area and rainfall rated are higher that infiltration rates
Overland flow: precip. infiltrated in areas of high infiltration and the rest is runoff
Subsurface flow: runoff infiltrate's and flows subsurface as throughflow to stream
What are the three different boundary layers
Viscous, Buffer and logarithmic (explain?)
Where does the maximum boundary shear stress occur?
where the water is the depth is greatest
Gilbert believed there was what type of relationship between landscaped and erosion
Dynamic Equilibrium
What areas have a high and low drainage density?
high: semi-arid climates
low: arid and humid areas
Extreme Value series, Partial Duration series, and Complete series
What is the difference between uniform, gradually varied, and rapidly varied flow
Uniform: v and d don't change over distance and energy line, water surface, and channel bottom are parallel
Gradual: V+D slightly changes over distance, most situations are assumed gradual flow
Varied: large and abrupt changed in depth and velocity
What is the difference between compactness coefficient and circularity ratio
CC: the ratio of the perimeter of watershed to the circumference to the circle with the same area
CR: Ratio of watershed area to area of a circle with the same circumference